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many of the usual criteria for judging the human authorship of stonework do not apply to such a tradition. Regrettably this seems to apply especially to the platform-angles method of testing which was so useful in distinguishing between human and natural work in England. Barnes’ (1939) platform-angles on a bifacially flaked tool are much lower than 90 degrees. Those on flakes and cores of an industry such as that of Texas Street are normally about 90 degrees. It should not be overlooked that plano-convex tools normally have high platform angles.” Plano-convex tools are those that are flat on one side and convex on the other. So here we have another example of an industry that was accepted (at least by Carter and his supporters) as being of human manufacture and that does not conform to the Barnes criterion.

In the preceding paragraphs, we have reviewed a number of stone tool industries that appear to be exceptions to the criterion proposed by Barnes. If these industries can be considered exceptions, then why not any or all of the various Eolithic industries that Barnes rejected?

Leland W. Patterson, the principal author of a recent study on the stone implements discovered at the Calico site in California, has also examined the application of the Barnes method. At Calico, stone objects believed to be of human manufacture have been found in strata dated by uranium series analysis to about 200,000 years before the present. They are, therefore, like the Texas Street implements, highly anomalous. We shall discuss these and similar finds relating to the human settlement of the Americas more fully in Section 3.8. For now, we shall confine ourselves to studying the application of the Barnes method to the Calico specimens, which are quite similar to Eolithic implements.

Barnes angle measurements were used by L. A. Payen (1982) to dismiss the Calico specimens. But L. Patterson and his coauthors (1987, p. 92) believed that measurement of Barnes’s angle was not suitable for this purpose. Patterson defined the Barnes angle, or beta angle (Figure 3.26), as “the angle between the ventral surface and the platform plane” (L. Patterson et al. 1987, p. 92). Patterson, however, preferred to measure the striking platform angle, which he defined as the angle between the dorsal surface of the flake and the platform plane (Figure 3.26).

Patterson observed: “For general lithic analysis, the striking platform angle is a better attribute than the ‘beta’ angle . . . because prominent bulbs of force on ventral surfaces of flakes can frequently interfere with ‘beta’angle measurement” (L. Patterson 1983, p. 301).

When Patterson and his coworkers measured striking platform angles rather than beta angles, their results differed from Payen’s: “Acute platform angles were found on 94.3% of the Calico flakes with intact platforms as compared with 95.5% of the experimental sample. The average platform angle of the Calico flakes was 78.7%, with a standard deviation of 8.3%. This is consistent with the usual products of intentional flaking” (L. Patterson et al. 1987, p. 97).

Figure 3.26. (1) The Barnes, or beta, angle, measured on a stone core. (2) The Barnes, or beta, angle, measured on a flake detached from the stone core. (3) L. Patterson’s striking platform angle, also measured on a detached flake.

Why such a difference from Payen’s findings? Patterson and his coauthors stated: “A question can be raised as to the nature of Payen’s sample. Only specimens that are candidates for representation as products of controlled flaking should be subject to analysis of platform geometry. A large amount of analytical ‘noise’ can be introduced by analyzing miscellaneous specimens of broken stone that possibly are not the result of controlled flaking. It is common in many lithic industries to find large quantities of non-diagnostic broken stone that are not the products of controlled flaking” (L. Patterson et al. 1987, p. 92). This might be true of some of the anomalously old European stone tool sites.

From Barnes’s report, it appears that he was measuring mainly